Graduation Semester and Year

Spring 2026

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Kinesiology

Department

Kinesiology

First Advisor

Paul J Fadel

Abstract

Given the heightened risk of cerebrovascular disease in Black adults in the United States, the overall aim of this dissertation was to investigate potential racial disparities in cerebrovascular responsivity among Black and White adults across both young, otherwise healthy individuals and patients with chronic kidney disease. This objective was addressed through two studies. First, cerebrovascular responsivity to acute aerobic exercise was assessed in young healthy Black and White adults. Second, cerebrovascular responsivity to hypercapnia was evaluated in Black and White adults with stages 3 and 4 chronic kidney disease (CKD). Chapter II demonstrated that cerebrovascular responses to acute aerobic exercise are comparable between young, otherwise heathy Black and White adults. Specifically, Black males exhibited similar exercise-induced cerebral hyperemia, reflected by comparable increases in middle cerebral artery velocity, as well as similar responses in cerebrovascular conductance index and cerebral pulsatility index relative to their White counterparts. These findings indicate that attenuated cerebrovascular responses to exercise are not present early in adulthood among otherwise healthy Black individuals. Chapter III demonstrated that individuals with stage 3 and 4 CKD do not exhibit an attenuation in cerebrovascular function assessed by cerebrovascular reactivity to hypercapnia (CVR) using a rebreathing protocol, cerebral autoregulation and cerebral pulsatility index, compared with age and comorbidity matched controls. Notably, racial comparisons within the CKD cohort revealed that, although CVR did not differ between Black and White adults within physiological ranges of hypercapnia, Black adults with CKD exhibited lower CVR than White adults when cerebrovascular reserve was challenged with a greater hypercapnic stimulus. These findings suggest that impaired CVR may not be a primary contributor to elevated cerebrovascular disease risk in adults with CKD; however, racial disparities are evident in cerebrovascular responsivity to greater levels of hypercapnia within this clinical population. Collectively, this dissertation provides novel evidence that cerebrovascular responsivity is comparable between young Black and White adults during exercise, yet racial differences appear to emerge in the context of CKD during hypercapnic challenge.

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Available for download on Wednesday, May 31, 2028

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